Clamp



FIG. 1 is a perspective view of a clamp showing our new design;

FIG. 2 is a side view elevation view thereof with the opposite side being a mirror image;

FIG. 3 is a top plan view thereof with the bottom plan view being a mirror image; and,

FIG. 4 is a rear elevation view. 

The ornamental design for a clamp, as shown and described. 